1. Field of the Invention
The present invention relates to methods for thermostamping thermoplastic composites; and, more particularly relates to a method for thermostamping composites involving radio frequency heating of the composite.
2. Description of Related Art
Radio frequency heating of thermoplastic composites in molding processes is known, see for example Thorsrud, U.S. Pat. No. 4,840,758. The molding processes involving radio frequency heating have, however, generally been relatively slow processes.
Convection heating of thermoplastic composites is also known, however, convection heating of composites made from non-woven, compressed, randomly dispersed fiber webs results in melting of the resin at the surface of the composite which allows lofting of the fibers at the composite surface resulting in insulation of the center of the composite thereby resisting heat transfer to the composite's center resulting in uneven heating across the thickness of the composite.
Accordingly, one object of the present invention is to provide a thermostamping method which provides quick heating of the composite with uniform heat distribution therethrough.